Penguins are birds that cannot fly, but they swim very well and spend most of their lives in the sea. There are 17 species of penguin.

Feathers: Penguins have shiny, waterproof feathers that help keep their skin dry. They have more feathers than most other birds - about 70 feathers per square inch. Each year, penguins molt, losing their old feathers and growing new ones. Some penguins have a feathery crest (like the Macaroni penguin and the Rockhopper penguin).

Anatomy: The Emperor Penguin is the largest penguin. It is up to 3.7 feet (1.1 m) tall and weighs up to 65 pounds (30 kg); this is bit less than half the size of an adult person. Males and females look very similar. All penguins have a big head, a short, thick neck, a streamlined shape, a short, wedge-shaped tail, and tiny, flipper-like wings. They have webbed feet which they use for swimming. Penguins are countershaded; they have a lighter color on the belly and a darker color on their back; this coloration helps camouflage them when they are in the water, hiding them from predators.

Habitat: All penguins live in the Southern Hemisphere (south of the equator). They live in climates ranging from the warm tropics to the frigid Antarctic. These defenseless birds usually live on predator-free islands or on remote parts of a continent. Some penguins, like the Emperor Penguin, live on pack ice in Antarctica.